Synthesis of a novel tri-substituted triazine monomer used for UV curable intumescent flame-retardant coating

A novel tri-substituted triazine in which substituted methacrylated piperzinyl (TMAPT) was synthesized and was then blended with di(acryloyloxy propyl) methyl phosphate (DAPMP) and pentaerythritol triacrylate (PETA) in different ratios to prepare UV curable intumescent flame-retardant coating. Their thermal stabilities and flame-retardant properties were studied by thermogravimetric analysis and limiting oxygen index (LOI), respectively. The results showed that the LOI values of the film increased almost linearly from 19.2% for C 10 N 0 to 25.2% for C 5 N 5 with increasing the content of TMAPT, which showed typical gas-phase flame-retarding mechanism. The FTIR spectra of the cured samples with increasing temperatures were measured, and the results indicated the potential expanding mechanism was that the nitrogen volatiles from TMAPT were wrapped by the char formed by catalyzing of poly(phosphoric acid)s, which was the degradation products of DAPMP. The expansion processes were monitored by a self-made equipment, which indicated the synergetic effect between TMAPT and DAPMP and further demonstrated the expansion mechanism. The sample PETA 4 DAPMP 2 TMAPT 4 (C 4 P 2 N 4 ) had the highest expansion degree of 126 among all samples. Moreover, thermal insulation properties of the cured coating were further measured, which also proved the synergetic effect between TMAPT and DAPMP.